Three action research projects explored the relative merits of several techniques for helping teachers modify classroom group processes. Project 1 compared a weekly seminar (using discussion of classroom research, problem-solving techniques, analysis of diagnostic data on the teachers' own classrooms, and followup discussion during the school year) to a four-week teacher development laboratory which employed the same techniques plus sensitivity training and role-play tryouts of new classroom practices. Project 2 explored the results of a program in which psychological consultants spent four hours each week for 15 weeks in small group discussions, classroom visitations, and individual conferences regarding teachers' group process management capabilities. Project 3 involved a six-day organizational development laboratory for school faculty which applied structured group exercises, small group discussions, and problem-solving techniques to interpersonal relations and staff communications problems. It was concluded that the faculty laboratory encouraged the use of new group processes in school organization and the classroom; that the consultation program, while changing teacher perceptions, did not change classroom behavior; and that the teacher development laboratory increased the likelihood that changes in teachers' cognitions and attitudes would be accompanied by classroom behavior changes. (JS)